1. Field of the Invention
The present invention relates to an array substrate, a method of manufacturing the array substrate and a liquid crystal display apparatus having the array substrate. More particularly, the present invention relates to an array substrate having enhanced opening ratio, a method of manufacturing the array substrate and a liquid crystal display apparatus having the array substrate.
2. Description of the Related Art
A liquid crystal display apparatus displays images by using liquid crystal. The liquid crystal display apparatus possesses many merits such as thin thickness, lightweight, etc. Therefore, the liquid crystal display apparatus has been widely used.
The liquid crystal display apparatus includes a liquid crystal display panel and a backlight assembly. The backlight assembly is disposed under the liquid crystal display panel to provide the liquid crystal display panel with a light.
The liquid crystal display panel includes a color filter substrate, an array substrate and a liquid crystal layer interposed between the color filter substrate and the array substrate. The color filter substrate includes color filters including a red color filter, a green color filter and a blue color filter. The color filters are arranged in a matrix shape. The color filters filter a light that passes through a pixel electrode to transmit the light having a specific wavelength. Hereinafter, a conventional array substrate will be explained.
FIG. 1 is a layout illustrating a conventional liquid crystal display apparatus, and FIG. 2 is a schematic cross-sectional view of the liquid crystal display apparatus in FIG. 1.
A conventional array substrate includes a thin film transistor 104, a storage electrode 103a and a pixel electrode 101. The thin film transistor 104, the storage electrode 103a and the pixel electrode 101 are opposite to a color filter (not shown) of a color filter substrate (not shown).
The array substrate further includes a data line 102 and a gate line 105. The is data line 102 and the gate line 105 are disposed between the color filters, and the data line 102 and the gate line 105 are extended along a region between the color filters.
The data line 102 is electrically connected to a source electrode S of the thin film transistor 104, and the gate line 105 is electrically connected to a gate electrode G of the thin film transistor 104. A drain electrode D of the thin film transistor 104 is electrically connected to the pixel electrode 101.
When a gate voltage is applied to the gate line 105, the thin film transistor 104 that is electrically connected to the gate line 105 is turned on, and a data voltage of the data line 102 is applied to the pixel electrode 101 through the thin film transistor 104. When the data voltage is applied to the pixel electrode 101, electric fields are generated between the pixel electrode 101 and a common electrode (not shown) of the color filter substrate. Therefore, an arrangement of liquid crystal molecules of a liquid crystal layer (not shown) disposed between the color filter substrate and the array substrate is changed to adjust optical transmittance to display images.
The storage electrode 103a supports a liquid crystal capacitor formed by the pixel electrode 101, the liquid crystal layer and the common electrode to maintain the data voltage. When the data voltage is applied to the pixel electrode 101, the storage electrode 103a prevents variation of the data voltage. The storage electrode 103a may be formed at edge portion of the pixel electrode 101.
According to the conventional array substrate described above, a light is leaked through an opening 106 between the data line 102 and the storage electrode 103a. Therefore, a light blocking layer 107 (or black matrix) formed at the color filter substrate or the array substrate is employed in order to prevent the light from being leaked through the opening 106.
The light blocking layer 107 blocks the opening 106. That is, in the conventional liquid crystal display apparatus, the light blocking layer is contained in the color filter substrate.
For example, the light blocking layer 107 has a left margin W4 of about 5 μm and a right margin W3 of about 6 μm, and a width W4 of right and left opening 106 is about 2.5 μm. As a result, a width of the light blocking layer 107 is about 22 μm. Therefore, an aperture ratio of the conventional array substrate is lowered due to the light blocking layer having wide width.
A light that passes through the opening 107 is diffracted to form a diffracted light. Therefore, when a distance between the light blocking layer 107 and the opening 106 increases, the width of the light blocking layer 107 increases in order to block the light. Therefore, reducing the distance between the light blocking layer 107 and the opening 106 is desirable in order to enhance the aperture ratio. However, reducing the distance between the light blocking layer 107 and the opening 106 is limited due to the liquid crystal layer. Therefore, enhancing the aperture ratio is also limited.
Furthermore, the light blocking layer 107 is formed on the color filter substrate, and a liquid crystal display apparatus is formed by assembling the color filter substrate and the array substrate. Therefore, even a minute misalignment may induce the light leakage. When a width of margin of the light blocking layer is increased in order to compensate the misalignment, the aperture ratio is also lowered.